Fluorocarbon sulfonic acid water and oil repellency agents

ABSTRACT

SEGMENTED FLUOROCARBON SULFONIC ACIDS COMPRISING THE REACTION PRODUCT OF A PERFLUOROALKYL-ALKYL HALIDE AND A SULFONATION REAGENT AS WELL AS THE ACID ANHYDRIDES, METAL SALTS, SULFONYL HALIDES AND SULFONAMIDES THEREOF. THE RESULTING COMPOSITIONS POSSESS UNIQUE SURFACE ACTIVE PROPERTIES AND THUS ARE APPLICABLE AS EFFECTIVE EMULSIFYING AGENTS. THEY MAY ALSO BE USED AS INTERMEDIATES IN THE PREPARATION OF WATER AND OIL REPELLENCY AGENTS

LJL LJL.

raw 4.

United States Patent 0 Int. Cl. C07c 143/1 U.S. Cl. 260-513 R 7 ClaimsABSTRACT OF THE DISCLOSURE Segmented fluorocarbon sulfonic acidscomprising the reaction product of a perfiuoroalkyl-alkyl halide and asulfonation reagent as well as the acid anhydrides, metal salts,sulfonyl halides and sulfonamides thereof. The resulting compositionspossess unique surface active properties and thus are applicable aseffective emulsifying agents. They may also be used as intermediates inthe preparation of water and oil repellency agents.

RELATED APPLICATION This application is a continuation-in-part of ourcopending application Ser. No. 18,720 filed Mar. 11, 1970, nowabandoned, which, in turn, was a continuation-inpart of Ser. No. 755,814filed Aug. 28, 1968, now abandoned, and assigned to the assignee of theinstant application.

SUMMARY OF THE INVENTION It is the object of this invention to preparenovel segmented fluorocarbon sulfonic acids and various derivativesthereof. Other objects and advantages of this invention will becomeapparent to the practitioner from the following description.

Thus, the compositions of this invention comprise the novel segmentedfluorocarbon sulfonic acids corresponding to the formula wherein Z is aradical containing from 3 to 20 carbon atoms inclusive and is selectedfrom the group consisting of straight and branched chain perfluoro alkylradicals, and

Y is a radical selected from the group consisting of alkylene,alkenylene, cyclo alkylene, bridged cyclo alkylene and ar-alkyleneradicals.

Also included within the scope of this invention are the derivatives ofthe specified fluorocarbon sulfonic acids including for example,

(a) anhydrides of these acids corresponding to the formula (ZY-SO O;

(b) metal and ammonium salts of these acids corresponding to the formula(Z-YSO )-,M+ wherein M is a metal atom or an ammonium group and a is thenumber of sulfonyl groups coordinated with said metal or ammonium groupand, correspondingly, the valence of said metal or ammonium group;

(c) sulfonyl halides of these acids corresponding to the formula Z--YSOX wherein X is a halogen atom 3,810,939 Patented May 14, 1974 iceselected from the group consisting of chlorine, bromine, and iodineatoms; and;

(d) sulfonamides of these acids corresponding to the formula ZY--$O -NR-wherein R is selected from the group consisting of hydrogen atoms andalkyl radicals; the Z and Y components of these derivatives being aspreviously described.

It will thus be seen that the novel sulfonic acid materials of thisinvention are basically four component compositions wherein thefluorocarbon group (Z) is linked to the sulfur atom of the sulfonylgroup via a hydrocarbon radical (Y), herein referred to as the segmentedgroup, and the sulfur atom is linked, in turn, to either a hydroxylgroup (acids), an oxygen atom (anhydrides), a metal atom (salts), ahalogen atom (sulfonyl halides) or, a nitrogen atom (sulfonamides).

DESCRIPTION OF THE PREFERRED EMBODIMENT In brief, the procedure forpreparing the novel composition of this invention ordinarily comprisesreacting:

(1) a perfiuoroalkyl-alkyl halide with (2) a sulfonation reagent; andthereafter, if desired, de-

rivatizing the reaction product to any corresponding form.

l-iodo-4-perfluoropropyl-n-butane, i.e. C F-;(CH ),I;lbromo-l1-perfluoroheptyl-n-undecane, i.e.

2-perfiuoroheptyl-S-bromomethyl-norbornane; 1 iodo-4-pertluoroheptyl-Z-butene, i.e.

I-bromo-ll-perfluoroheptyl-IO-undecene, i.e.

C F, CH=CH (CH gCHgBI' and, 1-iodo-2-perfluoropropyl-ethane, i.e. C F CHCH I.

Methods for preparing these perfluoroalkyl-alkyl halides are well knownto those skilled in the art (see U.S. Pats. 2,965,659 and 3,145,222).Typical preparative procedures include the addition reaction ofperfiuoroalkyl iodides and bromides with terminal olefins, and theaddition reaction of perfluorosulfonyl chlorides with terminal olefins.Where these procedures result in the preparation of secondary halides,such halides may be converted into the primary halides prior tosulfonation, or, may be sulfonated directly, as by means of theprocedures hereinafter described.

The sulfonation procedures which may be utilized to prepare the novelcompositions of this invention are also well known to those skilled inthe art. Among the sulfonation reagents that are used in theseprocedures are included alkali metal sulfites, alkali metal bisulfites,sulfuric acid, sulfur dioxide, sulfuryl chloride and chlorosulfonicacid. In a typical procedure, which is preferred for purposes of thisinvention because of its efiiciency and economy, one mole of theperfluoroalkyl-alkyl halide is admixed with from about one to two molesof an alkali metal sulfite and, thereafter, heated to a temperature offrom about 100 to 200 C. for a period of about 1 to 30 hours. Thereaction is conducted either in water or in a mixture of water and awater miscible organic solvent such, for example, as ethyl alcohol,isopropyl alcohol, dimethyl formamide and dimethyl sulfoxide. Thefluorocarbon sulfonic acid product is isolated as the alkali metalsulfonate which may, thereafter, be converted into the correspondingsulfonic acid or any other desired derivative.

Additional sulfonation procedures which may be utilized include: (1) thereaction of the fluoroalkyl-alkyl bromide and magnesium metal to producea Grignardtype magnesium bromide reagent and the subsequent reaction ofthis reagent with sulfur dioxide and chlorine gas to produce thefluoroalkyl-alkyl sulfonyl chloride; (2) the reaction procedure wherebythe fluoroalkyl-alkyl halide is first converted into the correspondingalcohol which, in turn, is reacted with sulfuric acid in the presence ofa neutralization agent, such as sodium hydroxide, potassium hydroxideand sodium carbonate, to produce the fiuoroalkyl-alkyl sulfate salt; theresulting salt then being reacted with an alkali metal sulfite toproduce the desired fluoroalkyl-alkyl sodium sulfonate salt; (3) thereaction of the fluoroalkyl-alkyl halide with thiourea or an alkalimetal thiocyanate to produce respectively the S- alkyl isothiouroniumhydrohalide salt or thiocyanate; these compounds can be converteddirectly into the sulfonyl chloride by treatment with aqueous chlorine;and (4) the direct sulfonation of a fiuoroalkyl-alkyl substitutedaromatic hydrocarbon with chlorosulfonic or sulfuric acid. Furtherinformation relating to the applicable sulfonation reactions may beobtained by referring to sulfonation and Related Reactions, by E. E.Gilbert, published in 1965 by Interscieuce Publishers, New York, N.Y.

Conversion of the novel compositions of this invention into thecorresponding acids, metal salts, anhydrides, sulfonyl halides andsulfonamides may be accomplished by means of well known derivatizationtechniques. Thus, the fluoroalkyl-alkyl sulfonic acids may be convertedinto metallic salts by reacting the acid with a metallic oxide,hydroxide, carbonate, etc., e.g. sodium carbonate, calcium oxide,potassium hydroxide, barium chloride and silver nitrate. The anhydridesof these acids may be prepared by heating the acid with a stoichiometricexcess of phosphorus pentachloride. The sulfonyl halides may be preparedby interaction of the acid with approximately an equimolar concentrationof a phosphorus halide such, for example, as phosphorus pentachloride.The resulting sulfonyl halides may, in turn, be reacted with liquidammonia, gaseous ammonia, ammonium carbonate or various amine compoundsin order to prepare the corresponding sulfonamides. Furthermore, where asulfonate salt is directly prepared by the sulfonation reaction, it maybe converted into the acid form by means of a decomposition techniqueusing dry gaseous hydrogen chloride in an appropriate solvent.

It should be noted that the novel compositions of this invention may beutilized in preparing additional fluoroalkyl-alkyl derivatives such, forexample, as amine salts, sulfones, sulfonic acid esters, substitutedsulfonamides and chloroamides.

As previously noted, these novel sulfonic acid compositions exhibitunique surface active properties. Thus, these materials are efiective inreducing the surface tension properties of both aqueous and non-aqueoussystems. Their unique characteristics enable them to be used as wettingagents, surface tension reducing agents, foaming agents, anti-foamingagents, dispersing agents, emulsifying agents, emulsion and dispersionstabilizers, detergents, corrosion inhibitors and fluxes, etc.

Furthermore, polyvalent sulfonate salts, e.g.

may be utilized to impart water and oil repellent properties to paperand paper products. Thus, such materials may be applied to paper fromwater-alcohol solutions by means of conventional tube and calendar-stacksizing techniques as well as by any other means which is capable ofeffectively depositing a small concentration of the repellent on thepaper. The novel derivatives may, of course, be successfully utilizedfor the sizing of paper prepared from all types of both cellulosic andcombinations of cellulosic and non-oellulosic fibers. The cellulosicfibers which may be used include bleached and unbleached sulfate(kraft), bleached and unbleached sulfite, bleached and unbleached soda,neutral sulfite, semi-chemical, chemi-groundwood, ground wood, and anycombination of these fibers. In addition, synthetic fibers of theviscose rayon or regenerated cellulose type as well as of the chemicallysynthesized type can also be used. It should be noted that as little asabout 0.1% of the repellent, based on the dry weight of the pulp in thefinished sheet, is sufi'icient to provide effective water and oilrepellency.

The novel sulfonic acid compositions of this invention may also be usedas intermediates in the preparation of water and oil repellency agentswhich are applicable for use on a wide variety of substrates.

The following examples will further illustrate the embodiment of thisinvention. In these examples, all parts given are by weight, unlessotherwise noted.

EXAMPLE I This example illustrates the preparation of afluoroalkyl-alkyl sodium sulfonate salt by means of an aqueous sulfitereaction technique.

A pressurized reaction vessel was charged with 38 parts ofl-iodo-2-perfluoropropyl-ethane. 22 parts of anhydrous sodium sulfite,40 parts of water, and 30 parts of ethyl alcohol. The temperature of thereaction system, which was in emulsion form, was raised to 120-125 C.over a period of four hours and the reaction allowed to proceed at thistemperature and a pressure of psi. for an additional 16 hours. Thereactor contents were then cooled and filtered.

Upon recrystallization of the solid product, a 76.5% yield ofsodium-(2-perfluoropropyl)ethane sulfonate was recovered in the form ofwhite platelets which melted at a temperature in excess 250 C. and whichexhibited slight solubility in both water and ethyl alcohol.

It should be noted that this reaction is suitable for preparing any ofthe sodium sulfonate reaction products in accordance with thisinvention. Thus, comparable sodium sulfonate salts may be produced byreplacing the above described fluoroalkyl-alkyl halide, in the reactionisgistem, with any of the following fluoroalkyl-alkyl ha- (a)l-iodo-4-perfluoropropyl-n-butane;

(b) l-iodo-l l-perfluoroheptyl-n-undecane;

(c) l-bromo-ll-perfluoroheptyl-n-undecane;

(d) Z-perfluoroheptyl-S-bromomethyl-norbornane; and (e)1-iodo-4-perfiuoroheptyl-Z-butene.

EXAMPLE II This example illustrates the preparation of additionalfluoroalkyl-alkyl sodium sulfonate salts typical of the novel productsof this invention.

A number of different fluoroalkyl-alkyl sodium sulfonate salts wereprepared according to the general procedure set forth in Example I,hereinabove, utilizing a variety of reagents at different concentrationlevels under varying reaction conditions. These variables are describedin the following table.

TABLE 160-5 1 120 Reaction time (hours) 6 18 Melting point 0.

EXAMPLE III This example illustrates a procedure for converting afiuoroalkyl-alkyl sodium sulfonate salt into its corresponding sulfonicacid.

A reaction vessel fitted with a gas inlet tube, a distillation apparatusand means for mechanical agitation was charged with 50 parts of diethylether and parts of sodium-(4-perfiuoroheptyl) butane sulfonate; thelatter fluoroalkyl-alkyl sodium sulfonate salt having been preparedaccording to the procedure set forth in Example 11-2. The resultingsuspension was maintained at room temperature and subjected to vigorousagitation whereupon dry gaseous hydrogen chloride was passed through thesystem for a period of three hours.

Upon completion of the decomposition reaction, the ether was removedfrom the system and the resulting product was washed several times withportions of fresh ether in order to remove the residual hydrogenchloride. The crude sulfonic acid was then vacuum dried andrecrystallized from benzene thereby yielding a white crystallinefluoroalkyl-alkyl sulfonic acid which melted at 102-106 C. and which wassoluble in water.

EXAMPLE IV This example illustrates a procedure for converting afiuoroalkyl-alkyl sodium sulfonate salt into its corresponding sulfonylchloride.

A reaction vessel fitted with a distillation apparatus and means formechanical agitation was charged with 20 parts of sodium (2perfluoroheptyl)ethane sulfonate, which was prepared according to thegeneral procedure set forth in Example 11-1, and 16.7 parts ofphosphorus pentachloride. An exothermic reaction occurred immediatelyand was accompanied by a brief period of phosphorus oxychloride reflux.Upon cessation of the exothermic reaction, the mixture was heated at 5060 C. for a period of two hours.

Thereafter, the reaction mixture was poured over 500 parts of crackedice, thoroughly dispersed therein by means of vigorous agitation, andfiltered. This procedure was repeated several times until the filtrateexhibited a neutral pH. The product was then dried, dissolved in acetoneand filtered free of unconverted fluoroalkyl-alkyl sodium sulfonate.Upon removing the acetone, an 86% yield of the correspondingfluoroalkyl-alkyl sulfonyl chloride was recovered in the form of a whitesolid which melted at 39-42" C. and which was soluble in heptane,benzene, ether and acetone.

EXAMPLE V This example illustrates a procedure for the conversion of afluoroalkyl-alkyl sulfonyl chloride into its corresponding sulfonamide.

A reaction vessel fitted with a gas inlet tube, a distillation apparatusand means for mechanical agitation was charged with 40 parts of benzeneand 13 parts of 2-perfluoroheptyl-ethane sulfonyl chloride, as preparedin Example IV. Anhydrous ammonia gas was then passed into the system ata rate which was sufficient to maintain the temperature of the systembetween 40 C. and 50 C. This procedure was continued for 30 minuteswhereupon the reacting product was filtered and washed with water toremove the residual ammonium chloride. The product was then dried andrecrystallized from water thereby producing an yield of a white solidfluoroalkyl-alkyl sulfonamide which melted at 98-104 C.

EXAMPLE VI This example illustrates the preparation of an aromaticfiuoroalkyl-alkyl sulfonic acid derivative.

A reaction vessel fitted with a reflux condenser, slow addition funnel,moisture trap, thermometer and means 'for mechanical agitation wascharged with 9.3 parts of chlorosulfonic acid to which was added over aperiod of sixty minutes, 13 parts of1-phenyl-3-perfluoroheptyl-npropane. The reaction was exothermic and theaddition rate was so regulated that the reaction temperature did notexceed 35 C. After the addition was completed, the reaction mixture wasstirred for an additional period of one hour at room temperature, andthereafter the mixture was slowly poured over cracked ice. Thefluorocarbon product was collected and dissolved in diethyl ether. Theether solution was washed with water until the wash water was neutral tolitmus and dried over sodium sulfate. Upon removing the solvent, thesulfonyl halide p (1H,1H,2l-l,2H,3l-I,3H perfluorodecyl) benzenesulfonyl chloride, was obtained in the form of a viscous yellow oil (13parts or 84% yield) and was thereafter converted into the correspondingsulfonamide which melted at 101-106 C.

EXAMPLE VII This example illustrates the preparation ofl-bromo-llperfluoroheptyl-n-undecane which was used as the startingmaterial for a compound illustrated in Example 11.

A reaction vessel as used in the previous examples was charged with 0.15gm. of u,a' azobisisobutyronitrile, 49.6 gm. (0.1 mole) perfluoroheptyliodide and 21.6 gm. (0.102 mole) undec-lO-enyl acetate. The reactionmixture was vacuum degassed using conventional freeze thaw techniquesand left under positive nitrogen pressure. The mixture was thereafterheated to 8590 C. and an additional 0.15 gm. of azobisisobutyronitrilein 5 ml. of t-butanol was slow added over a period of 3 hours. ResidualCqF15I was removed on completion of the heating period to yield crude 11-perfluoroheptyl-10-iodo-undecyl-l-acetate. The conversion was found tobe 91%.

A reaction vessel as used in the previous examples was charged with 30gm. of the product of Part A, ml. of anhydrous ethanol and 4 gm. ofgranular zinc. The mixture was saturated with dry hydrogen chloride andthereafter heated to 75 C. After heating for 1 hour at 75 C. anadditional 4 gm. of zinc was added to the reaction mixture and heatingwas continued for 5 hours. The mixture was periodically resaturated withdry hydrogen chloride so that an excess of hydrogen chloride was presentthrough the entire heating period.

At the completion of the heating period, the hot reaction mixture wasfiltered to remove unreacted zinc. The filtrate was poured into 400 ml.of distilled water and the oil layer was separated and dissolved indiethyl ether. The ether solution was then washed free of acid using anaqueous solution of sodium hydroxide (3%) and dried over sodium sulfate.The dried ether solution was fractionally distilled to yieldll-perfluoroheptyl undecane-1- 01. 23.2 gm. (87% yield) M.P. 50-53 C.,B.P. 140-145 C./ 0.4 mm. Hg.

Part C A reaction vessel equipped with a stirrer, condenser with dryingtube and thermometer, was charged with 23 gm. (0.04 mole) of the productof Part B and ml. of dry pyridine. At C., 8.3 gm. of phosphorustribromide (0.03 mole) was introduced into the reaction vessel. Thereaction mixture exothermed to 40 C. and was held at 3540 C. by means ofexternal cooling. When the exotherm of the mixture subsided, infraredanalysis of the crude reaction mixture indicated complete conversion ofthe alcohol to the brominated compound (no absorption at 3.0a).

The reaction mixture was thereafter poured onto cracked ice and drownedwith 200 ml. of water. The heavy oil which separated was collected,dissolved in ether and washed with water until the wash water wasneutral. The ether solution was dried over sodium sulfate, filtered, andvacuum distilled to strip the ether. The yield of purifiedl-bromo-l1-perfluoroheptyl-n-undecane was gm. (97% EXAMPLE VIII Thisexample illustrates the preparation of l-bromo-llperfluoroheptyl-lO-undecene which was used as the starting material fora compound illustrated in Example II.

In a suitable reaction vessel, gm. (approx. 0.05 mole) of crudell-perfluoroheptyl-lO-iodo undecyl 1- acetate, the product of Part A,Example VII, dissolved in 30 ml. of ethanol, was added at roomtemperature to a solution of 8.4 gm. of potassium hydroxide in 40 ml. ofa 3:1 mixture of ethanol and water. The resultant reaction mixture wasstirred and refluxed at 76 C. for a period of 3 hours. The crudehydrolysate was thereafter poured into 400 ml. of water and the oillayer was separated and dissolved in diethyl ether. The ether solutionwas washed with water until neutral and dried over sodium sulfate andfiltered. The dried ether solution was fractionally distilled to yield11 perfluoroheptyl 10- undecene-l-ol, 23.9 gm. (86% yield) colorlessliquid, B.P. 135140 C./0.5 mm. Hg. The product showed a strongabsorption at 3;!- (indicating --OH) and at 6;; (indicating CH=CH--).

8 Part B Following the identical procedure of Part C'of Example V11,19.9 gm. of the purified ll-perfluoroheptyl-lO-undeeene-l-ol prepared inPart A of this example was converted intol-bromo-ll-perfluoroheptyl-10-undecene, 16.1 gm. (72.6% yield).

Summarizing, it is thus seen that this invention provides for thepreparation of a novel class of segmented fluorocarbon sulfonic acidsand derivatives thereof.

Variations may be made in proportions, procedures and materials withoutdeparting from the scope of this invention which is defined by thefollowing claims.

What is claimed is:

1. A water and oil repellency agent selected from the group consistingof segmented fluorocarbon sulfonic acids corresponding to the formulawherein Z is a radical containing from 3 to 20 carbon atoms inclusiveand is selected from the group consisting of straight and branched chainperfluoro alkyl radicals; and

Y is a radical selected from the group consisting of alkylene, andalkenylene radicals;

s s-P."

References Cited UNITED STATES PATENTS 2,956,956 10/1960 Strauss et al2605l3 'R 3,282,875 11/1966 Connolly et al. 260513 R 3,337,615 8/1967Roberts et al 260--513 R 3,402,197 9/ 1968 Nychka 260-513 a R JOSEPH E.EVANS, Primary Examiner A. SIEGEL, Assistant Examnner U.S. Cl. X.R.

162-158; 252--15l, 555; 260-543 AR, 453 AL, 456 R, 491, 503, 505 R, 543R, 545 R, 556 A, 633, 653, 650 F

